Lead-copper-tin composition.



UNITED STATES PATENT oEEioE.

EDWARD D. GLEASON, OF NEW YORK, N. Y., ASSIGNOR T0 PLASTIC METAL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

LEAD-COPPER-TIN COMPOSITION.

No Drawing.

To all whom it may concern Be it known that I, EDWARD D. GLEAsoN, a. citizen of the United States, residing in Brooklyn, in the county of Kings, city and State of New York, have invented a certain new and useful Improvement in Lead-Copper-Tin Compositions, whereof the following is a specification.

My invention relates to plastic compositions including lead-copper and tin, which may be advantageously used in the manufacture of bearings for shafts, etc.

It is an object of my invention to provide such compositions free from lead sweats and segregation, which are defects usually found in such compositions due to lack of affinity of the lead for the copper or copper and tin, and the high specific gravity and low melting point of lead, for, at best, such compositions are but mechanical mixtures wherein copper is held in a finely divided state in a matrix of lead.

Another object of my invention is to provide such compositions including a given percentage of copper but of different degrees of hardness.

The effect of my improvement is to provide a composition which is homogeneous in that the copper therein is comminuted to the greatest possible extent and equally distributed throughout the mass of the composition. I have discovered that the effect aforesaid is attained by adding to the molten copper, in the process of making such compositions, a non-metallic derivative capable of increasing the miscibility of lead and copper, to wit, lead sulfid, and particularly the native lead sulfid, galena. I find it convenient to employ compositions containing lead, tin, lead sulfid, and from 50 to 60 per cent. copper. For instance, I fuse (30 pounds of copper and add thereto 5 pounds of galena and then gradually add, to said mixture, 30 pounds of lead and 5 pounds of tin.

Specification of Letters Patent. Application filed March 7, 1913. Serial No. 752,600.

Patented Nov. 4, 1913.

The fused mixture is then poured into pig, ingot or other suitable molds, and, when congealed, fracture thereof shows that the cast metal is homogeneous. served that such a mixture, without the galena, forms castings in which the tin is segregated forming strata.

Compositions of copper and lead, without tin, form the subject matter of my application Serial No. 7 52,601, filed March 7, 1918, for Letters Patent of the United States.

Moreover, the process herein contemplated, including the step in a process of making a tin alloy which consists in fusing with the alloy a, non-metallic derivative of the alloy metal other than tin, before mixing thetin therewith, forms the subject matter of my application Serial No. 758,833 filed April 1, 1913, for Letters Patent of the United States.

Although I have specified compositions containing 50 to 60 per cent. copper, as typical of my invention, I do not desire to limit myself to the precise methods of procedure or proportions herein set forth as it is obvious that various modifications may be made therein without departing from my invention as defined in the appended claims.

I claim 1. A composition containing lead, copper, tin, and lead sulfid.

2. A composition containing lead, tin, lead sulfid, and from 50 to 60 per cent. copper.

3. A composition containing lead, tin, a non-metallic derivative of lead capable of increasing the miscibility of lead and copper, and copper.

In testimony whereof, I have hereunto signed my name at Philadelphia Pennsylvania, this sixth day of March, 1913.

EDIVARD D. GLEASON.

Witnesses:

ARTHUR E. PAIGE, JOHN DOSGHER.

It may be ob- I 

